In a burner of an embodiment, a torch part includes: a torch combustor liner that is provided in a torch part casing and burns a fuel and an oxidant; a torch fuel supply part that supplies a fuel; a torch oxidant supply part that supplies an oxidant; an ignition device that ignites a fuel-air mixture; and a combustion gas pipe that is arranged at the center of the torch part and leads a combustion gas in the torch combustor liner to one end side of the torch part. A main fuel-main oxidant supply part includes: a main fuel supply passage formed in an annular shape on an outer periphery of the torch part; and a main oxidant supply passage formed in an annular shape on an outer periphery of the main fuel supply passage.

Embodiments in accordance with the present disclosure include a meta-stable detergent based foam generating device of a turbine cleaning system includes a manifold configured to receive a liquid detergent and an expansion gas, a gas supply source configured to store the expansion gas, and one or more aerators fluidly coupled with, and between, the gas supply source and the manifold. Each aerator of the one or more aerators comprises an orifice through which the expansion gas enters the manifold, and wherein the orifice of each aerator is sized to enable generation of a meta-stable detergent based foam having bubbles with bubble diameters within a range of 10 microns (3.9×10.sup.−4 inches inches) and 5 millimeters (0.2 inches), having a half-life within a range of 5 minutes and 180 minutes, or a combination thereof.

Embodiments in accordance with the present disclosure include a meta-stable detergent based foam generating device of a turbine cleaning system includes a manifold configured to receive a liquid detergent and an expansion gas, a gas supply source configured to store the expansion gas, and one or more aerators fluidly coupled with, and between, the gas supply source and the manifold. Each aerator of the one or more aerators comprises an orifice through which the expansion gas enters the manifold, and wherein the orifice of each aerator is sized to enable generation of a meta-stable detergent based foam having bubbles with bubble diameters within a range of 10 microns (3.9×10.sup.−4 inches inches) and 5 millimeters (0.2 inches), having a half-life within a range of 5 minutes and 180 minutes, or a combination thereof.

A gas turbine engine is provided. The gas turbine engine includes a turbomachine having a low speed spool and a high speed spool; a rotor assembly coupled to the low speed spool; an electric machine rotatable with the low speed spool for extracting power from the low speed spool, for adding power to the low speed spool, or both; and an inter-spool clutch positioned between the low speed spool and the high speed spool for selectively coupling the low speed spool to the high speed spool.

A gas turbine engine is provided. The gas turbine engine includes a turbomachine having a low speed spool and a high speed spool; a rotor assembly coupled to the low speed spool; an electric machine rotatable with the low speed spool for extracting power from the low speed spool, for adding power to the low speed spool, or both; and an inter-spool clutch positioned between the low speed spool and the high speed spool for selectively coupling the low speed spool to the high speed spool.

Methods and systems for starting an engine are described. The method comprises a manifold purging phase where the at least one fuel manifold is filled with an inert gas; a manifold fuel filling phase, where fuel flows into the at least one manifold and blends with the inert gas as the engine rotates, and the inert gas is subsequently turned off; and an ignition phase, where the fuel flowing from the at least one manifold into the combustor is ignited and light-up is detected.

Methods and systems for starting an engine are described. The method comprises a manifold purging phase where the at least one fuel manifold is filled with an inert gas; a manifold fuel filling phase, where fuel flows into the at least one manifold and blends with the inert gas as the engine rotates, and the inert gas is subsequently turned off; and an ignition phase, where the fuel flowing from the at least one manifold into the combustor is ignited and light-up is detected.

Chemical thrusters convert chemical energy predominantly into thermal energy and further into kinetic energy. These conversions are lossy and typically limit the usable thrust to 40-70% of the chemical energy (rockets). The exit velocity is maximized by increasing the temperature. However, temperature cannot be increased at will and can increase losses. Thrusters also have limited controllability under changing external conditions. The options for isochoric or detonative combustion are limited. This concept is intended to increase efficiency and controllability.

Through changes in catalytic loads and electromagnetic dose, combustion is increased and can be selectively regulated. Pressure/temperature are influenced and can be adapted e.g. to the changing external pressure. The achievable thrust increases due to the higher exit velocity. Further advantages exist. The geometry of combustion chambers can be optimized (e.g. smaller, more efficient). The concept is particularly promising for detonation engines or novel supersonic combustors.

Chemical thrusters convert chemical energy predominantly into thermal energy and further into kinetic energy. These conversions are lossy and typically limit the usable thrust to 40-70% of the chemical energy (rockets). The exit velocity is maximized by increasing the temperature. However, temperature cannot be increased at will and can increase losses. Thrusters also have limited controllability under changing external conditions. The options for isochoric or detonative combustion are limited. This concept is intended to increase efficiency and controllability.

Through changes in catalytic loads and electromagnetic dose, combustion is increased and can be selectively regulated. Pressure/temperature are influenced and can be adapted e.g. to the changing external pressure. The achievable thrust increases due to the higher exit velocity. Further advantages exist. The geometry of combustion chambers can be optimized (e.g. smaller, more efficient). The concept is particularly promising for detonation engines or novel supersonic combustors.

An injection system includes an inner nozzle body defining a first air path along a longitudinal axis. The first air path defines a converging-diverging section between an upstream portion of the first air path and an outlet orifice of the first air path. A main orifice is defined at a narrowest portion of the converging-diverging section. A fuel circuit wall is outboard of the inner nozzle body. A fuel path is defined between the fuel circuit wall and the inner nozzle body. An outer nozzle body outboard of the fuel circuit wall has a second air path defined through the inner nozzle body for communication of air from the outer nozzle body into the first air path, wherein the second air path meets the first air path at a second orifice in the first air path downstream of the main orifice of the inner nozzle body.